Since the 1.10.2.64Beta version of BambuStudio is the only one that works with the last X1C Firmware, it is mandatory to use it…
Well okay but…
It seems that Flow Dynamics & Flow Rate Calibration are not working, in manual or automatic mode.
It displays a progress bar with N/A written everywhere and the “next” button is disabled.
Log printer and studio out of the account and then restart and log back in on both.
Or open the BambuStudio.conf file and delete the entire CALIS section, after which all calibration related things revert to defaults and the buttons work again.